JPH0224324B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring the position, for example, the amount of protrusion, of an engine piston used in an automobile engine assembly line or the like.

The general structure of an automobile engine is mainly composed of a cylinder block in which a piston is assembled and a cylinder head superimposed on the upper surface of the cylinder block, and the overlapping surface of the block and head is a gasket. It is sealed with.

The piston, which reciprocates within the cylinder, is designed to slightly protrude from the top surface of the cylinder block at top dead center, but the amount of protrusion may vary depending on tolerances in piston assembly dimensions or deflection of the upper end of the block. There are microscopic variations within this range.

From this point of view, in order to eliminate variations in cylinder combustion operation, multiple types of gaskets with different thicknesses are prepared, and when assembling the engine, the type of gasket with a thickness that corresponds to the amount of piston protrusion should be selected and used. This creates a seal between the cylinder head and the cylinder head.

By the way, the conventional method for measuring the amount of piston protrusion is to use a measuring jig to determine the reference plane of the top of the block, and then measure the height of the top of the piston from the reference plane for each piston ( Japanese Patent Publication 1973-
40905), such conventional methods have the disadvantage that it is difficult to obtain good accuracy on the reference plane and that measurement requires a lot of effort, especially in multi-cylinder engines where the vertical length of the cylinder block is increased and the number of pistons is increased. This drawback is significant in the case of

The present invention has been made in order to eliminate the above-mentioned drawbacks. Namely, an object of the present invention is to provide an engine piston system that allows the position of the piston to be precisely measured by mechanical operation for each cylinder block. An object of the present invention is to provide a position measuring device.

The present invention will be described below based on an illustrated embodiment.

As shown in FIGS. 1 to 8, the measuring device of the embodiment is disposed in a space above a conveyor C on which cylinder blocks W are conveyed during the assembly process, that is, directly above the conveyor C. It is suspended from a rail 1 constructed on the ground. In addition, the second
The figure is a view seen from the left side of FIG.

Specifically, the lower half (not shown) of the carriage 2, which is slidable on the rail 1, is equipped with an elevating mechanism that is driven by pneumatic power when operated.
An upper end (not shown) of a hook-shaped head suspension rod 3 is connected to the lower end of the elevating mechanism.

Furthermore, a box-shaped measuring head 6 that faces above the cylinder block W is suspended from a long box-shaped fishing frame 4 fixed to the lower surface of the hanging rod 3 via a suspension mechanism 5. .

Further, the cylinder block W is connected to a two-stage upper and lower rail 10 installed directly below the rail 1 at a position inside the hook-shaped bent portion of the head suspension rod 3.
1, the conveyor C is suspended and supported via a block suspension lever 103, and the conveyor C and the block suspension lever 10
It is designed to be moved by the cooperation of 3.

Note that the measuring head 6 shown in FIGS. 1 and 2 is in a state in which it has been lowered to a position where it abuts against the upper surface of the cylinder block W, that is, in a state at the time of measurement.

The suspension mechanism 5 (see FIG. 8) includes link balls 7 and chains 8 that connect the fishing frame 4 and the measuring head 6 and carry the weight of the measuring head 6.
and a pair of molded coil springs 11 held between spring receivers 9 and 10 fixed to the lower surface of the fishing frame 4 and the upper surface of the measuring head 6, respectively, at two equidistant locations near the sides of the chain 8. This allows the measuring head 6 to oscillate to some extent against the shaping elasticity of the spring 11 when subjected to an external operational force in the horizontal plane.

Next, in the form of the measurement head 6, the bone structure is formed by the substrate 12 near the lower end of the measurement head 6.
and a waist board 1 erected around the four circumferences of the top surface of the board 12.
3, and a hanging plate 14 erected at the center of the board 12.
and a pair of frame boards 15 horizontally suspended at two locations at the upper end between the longitudinal wainscot boards 13,
The upper ends of the support columns 16 and 17 installed at the center of each width line of the hanging plate 14 and both frame plates 15 are screwed to the lower end of the chain 8 and the spring receiver 10, respectively.

In addition, the upper part of the waist board 13 and the lower part of the base plate 12 are covered by an upper cover 18 and a lower cover 19, respectively, and the chain 8 described above is
It is surrounded by a cylindrical floating cover 20.

Here, the cylinder block W to be measured (see FIG. 1) in the illustrated case is a 6-cylinder block, and
That is, a piston P is fitted into each of the cylinders No. 1 to No. 6, respectively, and in the illustrated state, the pistons P No. 1 and No. 6 are at the top dead center.

By the way, the lower end flange of each holding cylinder 21 is fixed to six locations on the upper surface of the base plate 12 at positions facing these pistons P, and a through hole is formed in the center of the fixed locations of the base plate 12. There is.

Further, the lower half of a spindle-shaped detector 22 made of a differential transformer, an air micrometer, a magnetic detector, etc. is fixedly attached to the upper end of the inner hole of the holding cylinder 21, and the spindle of the detector 22 is fixed to the upper end of the inner hole of the holding cylinder 21. A bearing block 25 that supports the midpoint of the measuring lever 24 in a see-saw manner is fixed to the lower end of the measuring shaft 23 which is integrally connected to the lower end and hangs down through the inner hole.

A pair of measuring elements 26 are provided at both ends of the measuring lever 24, and each measuring element 26 is provided with a pair of measuring elements 26 projecting downward.
6 is the symmetry 2 on the diameter of the upper surface of the piston P to be measured.
It is in contact with the point.

Note that the bearing block 25 is always pressed downward by a compression spring 36 for applying an appropriate measuring pressure to the probe 26.

Next, the intermediate portion of the spindle-shaped reference detector 27 is fixedly attached to the holding hole of the substrate 12 drilled near one side of each holding cylinder 21, and
The lower end of the measuring spindle 28 of the reference detector 27 is in contact with the upper surface of the cylinder block W.

Further, each of the three mounting holes, one in the center of one longitudinal end of the board 12 and two on the side of the other longitudinal end, has a reference foot 29 projecting downward.
is held so that its height can be adjusted, and the substrate 12
In two mounting holes in the longitudinal direction on one side of the cylinder block W, there are bushes 30 that protrude from opposite positions of the cylinder block W and fit into positioning pins (not shown).
It is held projecting downward and is height adjustable.

In addition, circular holes are formed on the substrate 12 on both sides of the hanging plate 14, and the upper half of the cylindrical electromagnet 31 is inserted into each circular hole. is screwed to the lower surface of a round lid-shaped mounting plate 32 fixed on the substrate 12.

The electromagnet 31 is a permanent magnet wound with a coil, and its magnetism is erased by energization. This is done for the purpose of preventing electric field interference caused by the electromagnet 31.

Finally, each waist plate 1 on both longitudinal end faces of the measuring head 6 is
An operating base 33 is fixed on the outer surface of the base 3, and a straight, rolling operating handle 34 protrudes from the center of the base 33. Below the handle 34 is an operating lever. 35 protrudes, and a lift control switch and an electromagnet control switch (not shown) attached to the inside of the base 33 are
They are each driven by rotating the handle 34 and gripping the lever 35. In other words, by turning either handle 34 clockwise (or counterclockwise), the carriage 2 can be raised or lowered. The mechanism moves up (or down), and by gripping (or releasing) either lever 35,
The electromagnet 31 is energized (or de-energized) to erase (or generate) magnetic force.

It goes without saying that the bottom plate of the lower cover 19 is provided with window holes for allowing the following members to escape.

Measuring head 26, spindle 28, standard foot 29, bush 30, electromagnet 31.

The operation and operation of the measuring device according to the embodiment constructed as described above will now be described. When the device is not in use, the measuring head 6 is raised at a position slightly higher than the height of the top surface of the cylinder block W. It is listed above.

First, after the cylinder block W to be measured is transferred to a predetermined position on the conveyor C while being supported by the block hanging rod 103, one of the handles 34 is lowered so that the cylinder block W is slightly lower than the cylinder block W. Lower the measuring head 6 to a higher height.

Next, while holding the lever 35, that is, keeping the electromagnet 31 in a non-magnetic state, push the handle 34 horizontally to move the carriage 2 directly above the cylinder block W.
The measurement head 6 is lowered while guiding the position to the positioning pin of the cylinder block W, and after the bush 30 is fitted, the handle 34 and Let go of lever 35.

As a result, the measurement head 6 stops descending and is densely superimposed on the upper surface of the cylinder block W due to the three-point contact action and the attraction action of the electromagnet 31. In this state, each spindle 2 of the reference detector 27
8 hits the top surface of the cylinder block W with a predetermined measuring pressure, thereby measuring the height of the top surface of the cylinder block W at each cylinder position.

Next, while the crankshaft of the cylinder block W is rotated 360 degrees, the upper surface of the piston P, which has risen to the top dead center, hits the pair of opposing probes 26, and the measuring lever 24 is moved by the measuring pressure of the spring 36. As a result, the top dead center height of each piston P is measured.

When all the pistons P have been measured, that is, after the crankshaft has made one revolution, the measuring head 6 is automatically raised above the cylinder block W in response to a lift command based on the measurement completion signal. Finally, the cylinder block W is sent out by moving the block hanging rod 103 along the conveyor C, and by repeating this operation, it is possible to continuously and efficiently measure a large number of cylinder blocks W. .

By the way, there are two methods for determining the amount of protrusion of each piston from the above-mentioned measured values.

(a) Method using the height from the reference plane Since the height of the reference plane passing through the three reference feet 29 is a known fixed value, the protrusion amount can be calculated from the above measured values of each detector 22 by calculation. demand.

This method is used when the top surface of the cylinder block W is finished into a precision flat surface, and it goes without saying that the reference detector 27 is not used when this method is used.

(b) Method using height from individual reference plane The amount of protrusion is determined from the difference between the measured value of each detector 22 and the measured value of each reference detector 27 near the same detector 22.

This method is adopted when the finishing accuracy of the upper surface of the cylinder block W is poor.

In order to select the type of gasket thickness to be used for assembly from the protrusion amount of each piston P determined in this way, selection is made based on the maximum value or average value of the protrusion amount of all pistons in the cylinder block W. It is normal to do so.

In the operation of the apparatus of this embodiment, since all measurements are performed by mechanical operations, the accuracy of the reference plane is stable and high-speed measurement is possible regardless of the number of cylinders.

In the above embodiment, the measuring head is lowered from above against a fixed cylinder head to perform measurements, but in contrast, the measuring head is fixed and the cylinder head is raised from below. It is also possible to measure

As described above, according to the engine piston position measuring device according to the present invention, the same number of detectors as the number of cylinders are arranged in a row on the measurement head, and the reference detection means is provided protruding from the lower surface of the measurement head. Since the measurement head is moved relative to the top surface of the cylinder head to measure the protrusion height of each piston, it is possible to obtain highly accurate measurements by stabilizing the measurement reference plane, and also to measure the protrusion height of each piston. It is also possible to carry out high-speed measurements, and thus has the effect of improving the operational characteristics of this type of position measurement.

Further, according to the present invention, the measurement surface by the detector 22 is the upper surface of the piston P reciprocating within the cylinder, and there is a problem that the measurement surface is microscopically tilted. 26 is formed by two measuring elements 26 held at both ends of a measuring lever 24 whose midpoint is swingably supported.
Since the average value of the points is used as the measured value, there is an effect that even if there is the above-mentioned inclination, no measurement error occurs and accurate measurement can be performed.

Furthermore, according to the invention, the measuring head 6
is made to be attracted to the multi-cylinder cylinder block W at the measurement position by the electromagnet 31, so that
It is possible to forcefully stop the relative movement of the measuring head 6 and the multi-cylinder cylinder block W, which has a long and heavy structure in the lateral direction, and to maintain an accurate positional relationship with the measuring head 6. This has the effect of allowing accurate measurements to be made.

[Brief explanation of drawings]

FIG. 1 is a front view of an engine piston position measuring device showing an embodiment of the present invention, FIG. 2 is a side view of the same, FIG. The figure is a front sectional view taken along the - line in FIG. 3, FIG. 5 is a side sectional view taken along the - line in FIG. 4, and FIG. 6 is an enlarged view of the measuring lever section in FIG.
7 is a side sectional view of FIG. 6, and FIG. 8 is an enlarged view of the suspension mechanism of FIG. 1. P... Piston, W... Cylinder block, 6... Measuring head, 22... Detector, 24... Measuring lever, 2
6... Measuring head, 27... Reference detector, 28... Spindle, 29... Reference foot.

Claims (1)

[Claims] 1. Each of the plurality of pistons P assembled in the multi-cylinder cylinder block W at the top dead center of the block W
In an engine piston position measuring device for measuring the position from the top surface, a measurement head 6 is provided so as to be movable relative to the top surface of a multi-cylinder cylinder block W, and the cylinder block provided in the measurement head 6 is provided. a reference detection means that can come into contact with the upper surface of W; and a plurality of detectors 22 that are mounted on the measurement head 6 and are provided facing each other at positions that can come into contact with each of the plurality of pistons P, each of which has a detection end thereof. The detector 22 has a configuration in which the midpoint of a measuring lever 24 holding two measuring elements 26 at both ends is swingably supported.
and an electromagnet 31 attached to the measurement head 6 and detachably attracted to the multi-cylinder cylinder block W.
the detector 22 in a state in which the reference detection means abuts against the upper surface of the multi-cylinder cylinder block W;
An engine piston position measuring device characterized in that the position of the piston P is detected when the measuring stylus 26 of the piston P comes into contact with the upper surface of the piston P at the top dead center. 2. The reference detection means is constituted by a reference leg 29 fixed to the measurement head 6, and the output of the detector 22 when the reference leg 29 abuts against the upper surface of the multi-cylinder cylinder block W. Claim 1, characterized in that the piston P position is configured to be detected based on the signal.
A device for measuring the position of an engine piston as described in Section 1. 3. The reference detection means is constituted by a plurality of reference detectors 27 which are provided near each of the plurality of detectors of the measurement head 6 and whose lower ends abut against the upper surface of the multi-cylinder cylinder block W. Claim 1 characterized in that the piston position is configured to be detected based on both the output signal of the detector 22 and the output signal of the reference detector 27 adjacent to the detector 22. The engine piston position measuring device according to item 1.